This application claims priority over Japanese Patent Application Ser. No. 110828/77 filed Sept. 14, 1977.
This invention relates to a surface treatment method whereby the surfaces of substrates such as paper, rubber, plastic and metal are treated and given nonadhesive properties, water repellency and wear resistance. Moreover, through the surface treatment of this invention, it is possible to improve the adhesive properties of substrates when coupling other polysiloxane compositions onto them. Various polyorganosiloxane compositions have been used up to now in the treatment of substrate surfaces in order to make them nonadhesive. Classified roughly, they are (1) a solution made by adding a Si-H bond containing polyorganosiloxane and/or an organoalkoxysilane to a polydiorganosiloxane having a hydroxyl group as a terminal group and by further combining this with an organic tin compound and organic solvent; (2) a water emulsion made by adding a Si-H bond containing polyorganosiloxane and/or organoalkoxysilane to a polydiorganosiloxane having a hydroxyl group as a terminal group and emulsifying this by adding polyvinylalcohol, etc., and (3) a composition made up of a polyorganosiloxane having 2 or more vinyl groups in its molecule, a polyorganosiloxane with Si--H bonds, platinum or each component of a platinum compound and organic solvent, and/or hardening inhibitor. These compositions are excellent in the sense that they provide non-tacky coatings on substrate surfaces, but when rubber or plastics are used as the substrate, there is a disadvantage in that the hardened silicone layer falls off easily from the substrate. Also, when natural rubber, ordinary synthetic rubber, or soft polyvinyl chloride are the substrate in the composition in (3), the vulcanizing agent, vulcanization accelerator, or plasticizer in these substrates often affect the activity of the platinum or the platinum compound in the composition thereby inhibiting the hardening of the composition. This invention eliminates the foregoing disadvantage and offers a treatment method that enables one to provide rubber and plastic surfaces, in particular, with excellent nonadhesiveness, water repellency, and abrasion resistance.